BSPGenerationTools.ZipFile.ExtractEntry C# (CSharp) Method

        public void ExtractEntry(Entry entry, Stream outputStream, ZipProgressHandler progressHandler = null)
        {
            if (entry.Offset >= _Stream.Length)
                throw new Exception("Invalid ZIP entry offset");

            _Stream.Seek(entry.Offset, SeekOrigin.Begin);

            byte[] buffer = new byte[1024 * 1024];

            _Stream.Read(buffer, 0, 30);
            ushort fileNameLength = BitConverter.ToUInt16(buffer, 26);
            ushort extraFieldLength = BitConverter.ToUInt16(buffer, 28);

            _Stream.Seek(entry.Offset + 30 + fileNameLength + extraFieldLength, SeekOrigin.Begin);

            Stream dataStream;

            switch (entry.CompressionMethod)
            {
                case 0:
                    dataStream = _Stream;
                    break;
                case 8:
                    dataStream = new System.IO.Compression.DeflateStream(_Stream, System.IO.Compression.CompressionMode.Decompress, true);
                    break;
                default:
                    throw new Exception("Unsupported ZIP compression method: " + entry.CompressionMethod + " for " + entry.FileName);
            }

            uint done = 0;
            while (done < entry.UncompressedSize)
            {
                int todo = (int)Math.Min(entry.UncompressedSize - done, (uint)buffer.Length);
                if (dataStream.Read(buffer, 0, todo) != todo)
                    throw new Exception("Cannot read data from ZIP stream for " + entry.FileName);

                outputStream.Write(buffer, 0, todo);

                done += (uint)todo;

                if (progressHandler != null)
                    progressHandler(done, entry.UncompressedSize);
            }

            if (dataStream != _Stream)
                dataStream.Dispose();
        }